The present specification relates to valves for aerosol containers, more particularly valves for aerosol containers for containing medicaments. The present specification also relates to aerosol containers having such valves fitted thereto and to methods for manufacturing such valves.
Pressurized metered dose dispensers have been known for over 50 years, particularly inhalers for the treatment of asthma, but also for other diseases where the lung, throat or nasal passages are suitable sites for delivery of drugs. A formulation of drug in such a dispenser is typically either in the form of a suspension or a solution in a propellant system, depending on the solubility of the drug in the formulation.
Medicinal aerosol formulations are often contained in a metal, plastic or glass vial or container equipped with a metered dose valve. The valve may be fitted to the body of the vial by crimping a ferrule, holding a valve assembly, against the body of the vial with an intermediate seal made of an elastomeric material compressed between the body and the ferrule. The intermediate seal can be in the form of a ferrule gasket placed and compressed between the top edge of the body of the vial and the opposing surface of the ferrule gasket, and/or it can be in the form of an O-ring placed around the body of the vial and compressed between the body of the vial and an annular flange of the valve ferrule.
U.S. Pat. No. 3,556,357 relates to closures of aerosol containers of the kind having a valve with a tubular stem passed with clearance through an aperture in the container cap, the stem carrying at its outer end the conventional head and nozzle whereas its inner end is provided with a flange. Two further such designs are disclosed in United Kingdom Patent Nos. 1,336,379 and 2,077,229.